IF ... THEN .... ELSEIF Construct

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`IF` ... `THEN` .... `ELSEIF` Construct

The IF construct has the following syntax,

 
IF(< logical-expression >)THEN

		 < then-block >

[ ELSEIF(< logical-expression >)THEN

		 < elseif-block >

 ... ]

[ ELSE

		 < else-block > ]

END IF

The first branch to have a true < logical-expression > is the one that is executed. If none are found then the < else-block >, if present, is executed.

For example,

    IF (x .GT. 3) THEN
     CALL SUB1
    ELSEIF (x .EQ. 3) THEN
     A = B*C-D
    ELSEIF (x .EQ. 2) THEN
     A = B*B
    ELSE
     IF (y .NE. 0) A=B
    ENDIF

IF blocks may also be nested.

For more information, click here

Next: Visualisation of IF ... Up: Control Constructs Previous: Visualisation of the IF